ROS压缩深度到numpy（或cv2）

Question

各位

我使用此链接作为起点，将我的compressedepth（图像类型：“32FC1；CompressedDepth，”以米为单位）图像转换为OpenCV帧：

Python CompressedImage Subscriber Publisher

当我试图打印时，我得到一个空数据，或者当我看到数组的结果时，我得到一个非类型，等等

转换压缩深度图像的正确方法是什么？ 重新发布对wifi/路由器带宽和速度限制是行不通的。在

Answer 1

解码compressedDepth的正确方法是首先从原始数据中删除头，然后转换剩余的数据。在

这在image_transport_plugins/compressed_depth_image_transport/src/codec.cpp中有记录。 在我的机器上，头大小是12字节。但是，这在其他体系结构上可能不同，因为没有定义枚举的大小。在

以下python代码段将压缩的16UC1和32FC1深度图像导出为png文件：

# 'msg' as type CompressedImage
depth_fmt, compr_type = msg.format.split(';')
# remove white space
depth_fmt = depth_fmt.strip()
compr_type = compr_type.strip()
if compr_type != "compressedDepth":
    raise Exception("Compression type is not 'compressedDepth'."
                    "You probably subscribed to the wrong topic.")

# remove header from raw data
depth_header_size = 12
raw_data = msg.data[depth_header_size:]

depth_img_raw = cv2.imdecode(np.fromstring(raw_data, np.uint8), cv2.CV_LOAD_IMAGE_UNCHANGED)
if depth_img_raw is None:
    # probably wrong header size
    raise Exception("Could not decode compressed depth image."
                    "You may need to change 'depth_header_size'!")

if depth_fmt == "16UC1":
    # write raw image data
    cv2.imwrite(os.path.join(path_depth, "depth_" + str(msg.header.stamp) + ".png"), depth_img_raw)
elif depth_fmt == "32FC1":
    raw_header = msg.data[:depth_header_size]
    # header: int, float, float
    [compfmt, depthQuantA, depthQuantB] = struct.unpack('iff', raw_header)
    depth_img_scaled = depthQuantA / (depth_img_raw.astype(np.float32)-depthQuantB)
    # filter max values
    depth_img_scaled[depth_img_raw==0] = 0

    # depth_img_scaled provides distance in meters as f32
    # for storing it as png, we need to convert it to 16UC1 again (depth in mm)
    depth_img_mm = (depth_img_scaled*1000).astype(np.uint16)
    cv2.imwrite(os.path.join(path_depth, "depth_" + str(msg.header.stamp) + ".png"), depth_img_mm)
else:
    raise Exception("Decoding of '" + depth_fmt + "' is not implemented!")